U.S. patent number 5,834,678 [Application Number 08/835,271] was granted by the patent office on 1998-11-10 for bullpup .50 caliber semi-automatic target rifle.
Invention is credited to Alan I. Kalb.
United States Patent |
5,834,678 |
Kalb |
November 10, 1998 |
Bullpup .50 caliber semi-automatic target rifle
Abstract
A shoulder fired semi-automatic rifle in the bullpup
configuration including a housing, a barrel projecting forward from
the housing, a bolt mechanism within the housing including but not
limited to a firing pin having a system to prevent movement via
inertia, a bolt mechanism that utilizes a slidable bolt locking
plate and a magazine that works with the bolt mechanism. The
trigger and pistol grip are mounted forward of the magazine and
ahead of the bolt, the trigger is connected to the hammer sear via
a transfer bar linkage.
Inventors: |
Kalb; Alan I. (Marlboro,
NJ) |
Family
ID: |
25269084 |
Appl.
No.: |
08/835,271 |
Filed: |
April 8, 1997 |
Current U.S.
Class: |
89/187.01;
89/191.01; 89/14.3; 42/75.02 |
Current CPC
Class: |
F41A
3/46 (20130101) |
Current International
Class: |
F41A
3/46 (20060101); F41A 3/00 (20060101); F41A
003/44 () |
Field of
Search: |
;89/185,187.01,187.02,191.01,192,14.3,182 ;42/75.02 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Johnson; Stephen M.
Claims
I claim:
1. A rifle comprising:
(a) a lower receiver assembly;
(b) an upper receiver assembly having a bolt carrier assembly
slidably located therein, said upper receiver is attached to lower
receiver assembly;
(c) a buffer spring assembly mounted in said upper receiver and
arranged to cause said bolt carrier to be urged forward;
(d) a rifle barrel having a cartridge chamber, said barrel being
fixed to said lower receiver, in which said barrel is arranged to
mate with a bolt;
(e) a gas operated system in which high pressure gas is directed
from said barrel through a gas block to said bolt carrier
assembly;
(f) said bolt having two sections, a front and a rear, the front
being cylindrical in shape to engage said barrel, the rear being
octagonal so as to engage in a slidable fashion said bolt
carrier;
(g) a bolt locking plate having a locking lug section to engage a
lower receiver locking lug receiver, and a portion on the opposite
end to receive a dovetail rail of said bolt carrier.
Description
BACKGROUND
The need for a .50 semiautomatic target rifle in the "Bullpup"
configuration cannot be underestimated. A rifle of this type has
many applications in both the civilian and military sector. The
civilian market has been clamoring for a .50 caliber semiautomatic
rifle for target shooting which could be accurate to 1000 yards
while at the same time being compact, reliable and lightweight. My
unique design uses many features which accomplish these desired
results and make this rifle suitable for military applications.
The idea that a target rifle be less than 30 lbs is critical in my
design. The reason it is desirable for the rifle to be less than 30
lbs is for practical purposes, if a target shooter wishes to use
the rifle in any position other than prone, the rifle has to be
light enough so that the shooter will not become fatigued to
quickly. The military also requires a rifle of this type be light
enough so that it can be transported easily by small units, and the
lighter the rifle means that the troops can carry more ammunition
and equipment thereby making them more tactically versatile.
The concept of a compact .50 caliber semi automatic target rifle is
also very attractive to both civilian and military users. By making
the rifle physically shorter it becomes easier to balance and is
quicker to aim. The speed with which a user can acquire a target
and successfully engage it is critical to the military because in
combative situations that speed could mean the difference between
hitting and missing an enemy target. In the civilian world speed in
acquiring the target is also important because when competing in a
shooting match one of the constraints is time, the user may only
have a few seconds with which to engage their target.
Accuracy goes to the heart of the purpose of the rifle. Accuracy
has always been a prerequisite by both civilians and the military
when selecting a rifle. The ability to accurately engage targets at
progressively longer distances has been the goal of all rifles
designers since the invention of the musket. By harnessing the
immense power of the .50 caliber cartridge and by projecting it
accurately it is possible to engage targets in excess of 2000
yards. For the military this means that an enemy target could be
engaged long before that enemy target could engage our forces.
The desire for reliability cannot be overstated, whether in
competition or combat, a rifles reliability is paramount to the
safety of the user. One need only image the deadly consequences of
jammed rifle in a combat situation or a ruined weekend for a target
shooter who has lost a match due to a faulty rifle.
For the foregoing reasons, there is a need for a bullpup .50
caliber semi-automatic target rifle that is compact, accurate and
reliable.
SUMMARY
The present invention is directed to a bullpup .50 cal
semi-automatic target rifle that satisfies these needs [needs
identified in Background section]. A bullpup .50 cal semi-automatic
target rifle having features of the present invention comprises a
barrel, a gas tube assembly, a lower receiver, an upper receiver, a
trigger assembly, a bolt carrier, and a bolt assembly.
The unique design uses a sliding locking bolt lock which converts
linear motion in the horizontal direction to linear motion
unlocking the bolt lock in the vertical direction, further my
invention uses a linked bolt carrier gas piston assembly which
eliminates the need for a giant recoil spring, instead a large gas
piston spring supplemented by twin horizontally mounted receiver
springs take up the recoil of the giant .50 caliber cartridge. The
sliding bolt lock is keyed to a high angle slope on the bolt
carrier, which is connected to a gas carrier linkage that is
affixed to the gas piston.
The size of the rifle is quite compact because of the unique bolt
locking lug plate system combined with the gas piston/bolt linkage
assembly. To further reduce size and simplify the design I used a
side trigger hammer assembly. While the pistol grip and trigger are
mounted in the traditional vertical manner the hammer and sear
assembly is mounted on the left side of the lower receiver in a
blister which allows the massive bolt carrier more room within the
receiver.
By mounting the hammer on 90 degree angle I further reduced size
while maintaining fast timing and positive locking. Several unique
safety features prevent the rifle from firing out of battery. Both
the bolt carrier and the locking lug plate must be in forward
locked position before the trigger is allowed to connect with the
disconnector firing sear. This feature prevents a possible case
head rupture form firing out of battery. The upper receiver is
removably affixed to the lower receiver by means of a sliding rail
system; because of the use of a machined lower receiver the upper
receiver can be fabricated form sheet metal to reduce overall
weight. The complete rifle is both lighter and more compact than
any of it's contemporaries.
Previous .50 caliber semi-auto rifles were relatively large and
cumbersome and heavy. This was necessary in order to facilitate the
large and extremely powerful .50 caliber BMG cartridge. Because of
the strength of the round all previous systems depended upon heavy
components thereby increasing the overall weight of the rifle. The
increased weight of subsequent rifles made them awkward to carry
and use in the field. By reducing the rifles size and weight but
retaining the immense fire power of the .50 BMG cartridge my system
will allow the individual soldier to carry more ammunition and
equipment thereby increasing the soldiers potential effectiveness
in the field.
The recoil control system consists of the twin recoil springs, a
large gas piston spring and the multiple chambered muzzle brake.
The twin bolt recoil springs assist the gas piston recoil spring in
returning the bolt to battery. The last piece is the recoil
arresting multi ported muzzle break which acts to divert gasses
away from the muzzle.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 Is an enlarged side elevation of a semi-automatic rifle made
in accordance with this invention, with portions broken away.
FIGS. 2 through 8 show the components of the rifle made in
accordance with this invention in their various positions during
the firing cycle, the views are from one side, and partially broken
away and in longitudinal cross section.
FIG. 2 shows the rifle of the invention with a handle for
retracting the bolt carrier to the rear held in a rearward position
just prior to releasing.
FIG. 3 shows the components of the gun in their respective
positions as a cartridge is raked out of the magazine.
FIG. 4 shows the rifle of the invention as the bolt locking plate
begins to be forced into the locking plate space by the bolt
carrier.
FIG. 5 shows the position of elements of the rifles of the
invention as the trigger is released.
FIG. 6 depicts the gas piston forcing the bolt carrier rearward
thus unlocking the bolt locking plate and said bolt carrier
continuing to travel rearward over the hammer of the gun of the
invention, thus cocking the hammer.
FIG. 7 shows how the fired casing is ejected from the rifle of the
invention, through a port on the side of the rifle of the
invention.
FIG. 8 shows how the cycle is completed when the bolt carrier stops
and another cartridge is raked out of the magazine.
DETAILED DESCRIPTION
Referring now to the drawings in more detail, action mechanism;
bolt locking features; the bolt 10 has a rearward octagonal female
portion which is threaded to receive the threaded cylindrical male
forward portion; the bolt 10 is slidably affixed to the bolt
locking plate 20 which moves in an up and down motion while the
bolt is retained by a dovetail rail 4, the bolt locking plate 20 is
slidably affixed to the bolt carrier 21 which transmits horizontal
motion the bolt locking plate 20 which is converted by the locking
plate 20 into vertical motion. Thus the bolt locking plate 20 rises
out of the locking lugs in the mating receiver 9 and begins a
rearward travel. The bolt 10 remains stationary while the bolt
locking plate 20 is moving horizontally and the bolt carrier 21 is
moving vertically. When the bolt locking plate 20 ceases to travel
vertically and begins it's rearward travel it begins to bring the
bolt 10 with it in the direction of travel of the bolt carrier 21,
the entire assembly is now moving in the same direction.
At the rearward stroke, the bolt 10 extracts and ejects the spent
cartridge casing 30 being assisted by gases from the cartridge 30.
As the bullet travels down the barrel 8 it reaches the gas port 31,
a small hole in the barrel 8, the bullet passes the hole and small
amount of high pressure gas from the expanding cartridge 30 enters
the hole and is directed rearward against the gas piston 14 which
is then forced rearward, this causes the piston 14 which is
attached to the bolt carrier 21 via the bolt carrier linkage 32 to
push the bolt carrier 21 rearward unlocking the bolt locking plate
20 which is slidably attached to the bolt 10. This in turn causes
the bolt 10 to be forced rearward extracting and ejecting the spent
cartridge casing 30.
The trigger mechanism is comprised of a trigger 23 a trigger return
spring 33 a trigger transfer bar 5 a disconector sear 6 and a
hammer 7. The second stage is mounted 90 degrees on the left of
vertical. This allows the design to remain quite compact without a
trigger mechanism taking up valuable space. The trigger 23 is
depressed which is placed against the transfer bar 5 which contacts
the hammer sear, this is unlocked by the dissconector 6 which is a
secondary safety which prevents the sear from accidental release,
once the disconector releases the hammer sear, the hammer 7 is
propelled by spring force to make contact with the firing pin 1.
The firing pin 1 then travels forward making contact with the
primer of the chambered cartridge 30 with sufficient inertial force
to detonate the primer discharging said cartridge 30.
The firing pin inertia spring 36 prevents the pin 1 from travel
until it has been impacted by the hammer 7. The firing pin inertia
spring 36 is housed in the bolt 10 and is sandwiched between the
bolt 10 and around the firing pin 1 itself The pin 1 is designed to
prevent over travel, breakage and specifically to prevent the
inertia of the bolt 10 from causing it to travel. The firing pin
sub assembly consists of a firing pin 1, firing pin spring 36 and a
firing pin retaining block 28. All of which are housed in the bolt
10. The firing pin 1 is kept static via the firing pin spring 36
and the firing pin retaining block 28. The retaining block 28
prevents the pin 1 from falling out of the bolt 10 while the
combination work together to hold the pin 1 under a limited load
via spring tension until the hammer 7 is released.
* * * * *